The Frontier Lord Begins with Zero Subjects: Volume 5 by Fuurou

When a family of cavekin people arrive in Iluk Village, Dias gets a history lesson and three new residents ready to work as blacksmiths. However, before they can get started actually making anything, Dias will have to help them acquire the materials they need to build and work their furnace. But the cavekin aren’t the only visitors with business in Iluk. There’s a councillor from the Beastland Kingdom, a former civil servant determined to see his orders to completion, and...a fire-breathing dragon hellbent on razing Iluk Village to the ground!